It is known that some benzothia(dia)zepine derivatives function as inhibitors of IBAT (Ileal Bile Acid Transporter) (Patent Document 1). The inhibitors of IBAT are useful in the treatment of dyslipidemic conditions and disorders such as hyperlipidemia, hypertrigliceridemia, hyperbetalipoproteinemia (high LDL), hyperprebetalipoproteinemia (high VLDL), hyperchylomicronemia, hypolipoproteinemia, hypercholesterolemia, hyperlipoproteinemia and hypoalphalipoproteinemia (low HDL).
In addition, the benzothia(dia)zepine derivatives mentioned above are also useful in the treatment of functional constipation and constipation-dominant irritable bowel syndrome (C-IBS) (Patent Document 2 and Patent Document 3).